DALLAS (CBSDFW.COM) – Law enforcement sources confirmed to CBS 11 News all three package bombs that exploded in Austin in less than two weeks had shrapnel and some kind of motion triggered detonation component.

“The only thing you can probably say with any assuredness, they’re going to continue and you’ve got to get them stopped,” said former FBI agent, Danny Defenbaugh.

Defenbaugh spent decades investigating deadly explosions like the Oklahoma City Bombing as a bomb tech for the bureau.

Three bombs concealed in packages were detonated in Austin over the past ten days and police said they are connected. In all three cases, the packages were left on the doorstep and were not delivered.

“It’s more vile in the intentions,” said Defenbaugh. “You don’t know who’s going to pick it up.”

The first happened March 2nd where the package was delivered to the doorstep of Anthony Stephan House. The blast killed him.

The second exploded ten days later, killing 17-year-old Draylen Mason.

The same day, just hours later a third bomb detonated, injuring a 75-year-old woman.

“Once you build them, it’s delivered and you don’t kill yourself, then normally you’re going to find that each and every time the bomb is going to be built the same way,” said Defenbaugh.

He believes investigators are focusing on the mechanics more than the motive.

“You reconstruct the explosive device and you go from there backwards,” said Defenbaugh.

All the victims are either African American or Hispanic.

Defenbaugh, like investigators, said focusing on any one particular aspect this early in the case could delay catching who is responsible.

“Anybody with hate in their heart is going to think up something,” said Defenbaugh.

While Dallas Police and other North Texas law enforcement departments are issuing local awareness advisories because of what is happening in Austin, Defenbaugh is stressing vigilance and not panic.

“That’s like telling someone, don’t go shopping because someone blew up a mall in Beirut, Lebanon for example,” said Defenbaugh. “You don’t want to live your life and change it so that you live in fear.”

Austin Police are encouraging anyone who sees a suspicious package to report it to authorities.